1. Field of the Invention
The present invention relates to an electric endoscope provided with a driving section that rotationally drives an object to be driven.
2. Description of the Related Art
In recent years, an endoscope has been broadly used in a medical field and an industrial field. Particularly, in the medical field, an endoscope that is easy for a surgeon to operate when performing treatment or the like for remedy by grasping the endoscope has been desired.
For example, in Japanese Patent Laid-Open Publication No. 2007-37564 as a first conventional example, it is configured that an ultrasound transducer to be rotationally driven is housed in a transducer housing portion provided at a distal end portion of an insertion portion, and the ultrasound transducer is rotationally driven by a motor provided in an operation portion through a flexible shaft inserted through the insertion portion, to thereby enable radial scanning by ultrasound, by the ultrasound transducer. Further, it is disclosed to cope with rotation delay by providing an encoder in the vicinity of a proximal end of the ultrasound transducer and detecting the rotation delay of the flexible shaft by the encoder.
Further, in Japanese Patent Laid-Open Publication No. 2007-44074 as a second conventional example, there is disclosed a configuration in which an ultrasound probe is insertable into a treatment instrument insertion channel of an endoscope, an ultrasound transducer is mounted at a distal end portion of a flexible shaft which is inserted through the ultrasound probe, a rear end of the flexible shaft is connected to a motor unit and the ultrasound transducer is rotationally driven by the motor unit through the flexible shaft. Further, it is disclosed to detect a rotational position of a distal end of the flexible shaft with high precision by an encoder provided at the distal end of the flexible shaft, and obtain a detailed ultrasound tomographic image by radial scanning.